Gauge



R. D. HUBBS June 3, 1952 GAUGE Filed Oct. l, 1948 INVENToR. RAYMOND D.H0585 R. D. HUBBS GAUGE June 3, 1952 Filed Oct. l, 1948 2 SHEETS-SHEET 2IN V EN TOR.

RAYMOND D. HUBBS b ATTORNEYS Patented June 3, 1952 UNITED STATES PATENTCFFICE 1 Claim.

This invention relates to a gauge and more particularly to an inspectionor checking gauge primarily intended for use in checking therelationship between the axes of intersecting surfaces, as in an articlewhich has a bore and an intersecting cross hole or in an article whichhas an outer cylindrical surface and a cross hole.

In the manufacture of machinery or apparatus it is not uncommon tomass-produce parts such as crank arms or levers according to a patternin which the part has a bore by means of which the part is mounted on ashaft and in which the part and the shaft are drilled or bored crosswiseof the axis of the shaft to provide a crossl hole which receives a pinfor fixing the part to the shaft. In such cases, it is obvious that theaxis of the cross hole must bear the same relationship to the bore inthe part as it does to the outer cylindrical surface of the shaft. Inthe simplest example, the axis of the cross hole should theoreticallylie on a diameter of the inner cylindrical surface forming the bore inthe part or of the outer cylindrical surface forming the outsidediameter of the shaft. It will further be obvious that misalignment ofthe cross hole with respect to one or the other of the parts will renderit diicult if not impossible to insert the connecting pin when the partsare assembled.

Special jigs and fixtures have heretofore been devised for setting upthe parts in the drilling or boring operation so that the correctrelationship between the bore or outer surface and cross hole will beobtained. However, because of Wear in the xtures incident to usethereof, it is expedient to check these fixtures from time to time toascertain whether tolerable accuracy is being maintained. The simplestform of check can be made by an inspection of the product itself; thatis to say, the relationship between the Ybore or surface and the crosshole can be measured and the inaccuracy, if any, determined, whereuponthe necessary adjustment may be made in the manufacturing equipment ifsuch adjustment is required. As is well known, such checking of-thefinished articles is made from time to time by inspecting personnelequipped with the necessary instruments. l

The instruments heretofore known and used for the purpose of making theinspection referred to above included, among other things, a surfaceplate, V-blocks, indicators, and height gauges. These instruments had tobe set up from time to time according to the particular -job andconsiderable time and effort were involved in making the requisiteinspection. In addition, the inaccuracy in the relationship between thebore or surface and the cross hole had to be completed and reduced tofamiliar units of linear measurement, such as thousandths ofl an inch,so that it would be known what adjustment to make in the drilling orboring apparatus.

According to the present invention, the complicated system of inspectionis eliminated and is replaced by a simple procedure involuving the useof a gauge including means providing a pair of longitudinally extending,non-parallel edges representing respectively the base and the hypotenuseof an imaginary right triangle. The base edge of the gauge is providedwith a scale including indicia in the form of a plurality of graduationsrepresenting units of linear measurement, such as thousandths of aninch. The taper of the hypotenuse edge, or the angle between the edges,is in thousandths of an inch, for example, and the scale and taper areso related that the taper in thousandths of an inch per inch is twicethat of the number of graduations per inch on the scale. In one form ofthe invention, for the purpose of checking the relationship between abore and a cross hole, a pin is inserted through the cross hole so as todivide the bore into substantially equal halves; the gauge is insertedinto the bore with the scale edge lying along an element of thecylindrical surface forming the bore, the tapered edge engaging theproximate side of the pin. The extent to which the gauge can be insertedbetween the pin and the proximate surface portion of the bore isdetermined by the wedging action that occurs between the gauge and thepin. This extent of insertion is read on the scale on the gauge. Thegauge is then withdrawn and reinserted at the opposite side of the pinand a similar reading taken on the scale. The two are compared and thedifference, if any, in thousandths of an inch is noted. If thedifference is within the accepted tolerances, no adjustment need be madein the manufacturing equipment. However, if the difference is outsidethe accepted tolerances, the reading will immediately indicate to whatextent the equipment must be adjusted.

On the basis of the foregoing, it is accordingly a principal object ofthe invention to provide an improved gauging or inspection means that issimple in construction and accurate and eiiicient in use and one thatmay be' readily'substituted for previouslyknown methods and devices withpronounced savings in time. labor, and skill ofpersonnel involved. Y Y

A further important object of the inventionis to adapt the gauging meansreferred to above for use in articles or parts in which the surfacesurrounding the bore to be checked is irregular, to the end that thecomparative readings can be taken on the same or a similar point so thatthe readings will be accurate. In this respect, it is an object toprovide a simple and inexpensive instrument or gauge.

A further object is to utilize the principles of the invention for thepurpose of checking the relationship of a cross hole to an externalsurface, such as in the case of a cylindrical shaft having a cross holetherethrough. In this form of the invention, it is an object to providea simplified instrument or gauge comprising relatively few moving partsand to provide one of the parts with an easily readable scale whicheliminates computation and the application of mathematical formulae.

The foregoing and other important objects and desirable featuresinherent in and encompassed by the invention will become apparent tothose `skilled in the art as preferred forms of the invention are fullydisclosed in the following detailed description and accompanying sheetsof drawings in which: Y

Figure lis a side elevational view of a preferred form of gauge forchecking the relationship between a bore and a cross hole;

Figure 2 is an end elevational view of the structure of Figure 1, theview being taken in the direction indicated by the arrows on the line 22 -of Figure l;

' Figure 3 is a perspective View of a representative article or part onwhich the gauging or inspecting operation can be performed by the gaugeshown in Figures 1 and 2;

Figure 4 is an end elevational view of the part or article shown inFigure 3;

Figure 5 is a View illustrating the procedure -in checkingA therelationship between the bore and cross -hole in an article such asillustrated in .Figures 3 and 4;

Figures 6 and 7 are views illustrating successive steps in the procedureinvolved in checking an article or part such as that shown in Figures 3and 4 but in which such part or article Vhas an irregular surfacesurrounding the bore;

Figure 8 is a view of a modified form of the invention embodied in agauge for the purpose of checking the relationship between a cross hole'and the outer surface of a shaft, the shaft or 4part being representedin section in the view;

Figure 9 is a perspective view of such part or Figure 10 is an endelevational view of the 'gauge shown in Figure 8;

Figure 11 is a fragmentary plan elevational View of the gauge shown inFigure 8 as viewed along the line I of Figure 8; and

Figure 12 is a view of a further modified form of instrument.

In the drawings, the yl, 2, 5, 6 and 7 is drawn to a scale in which nineinches equal one foot. The scale of the drawing of the gauge in Figures8, 10 and 1l is full sized. In each case, due allowance must be made forreduction of the drawings in the printing of patent copies.

As the description progresses, it will become apparent that theprinciples of the invention may be readily utilized in the gauging orinspection of parts or articles differing somewhat from thoseillustrated; for example, the parts may Yhave surfaces -orconfigurations differing from Vthose illustrated. Likewise, thecalibration of thescaleand the relationship of the taper Ytheregaugeshown in Figures to may be made in accordance with units of measurementother than thousandths of an inch. The examples illustrated arerepresentative of part shapes and units of linear measurement mostcommonly used in this country.

The part to be checked, as shown in Figures 3 and 4, is designated inits entirety by the numeral 20 and is provided with an axial bore 2|which provides a surface of generation about an axis A-A (Figures 3 and4). The upper surface of the part 20 that surrounds the bore 2| isprovided as a substantially flat radial surface 22. The part is furtherprovided with a cross hole 23-23 which theoretically has its axis B-B(Figure 4) coinciding with a diameter of a circle included in theinternal cylindrical surface of the bore 2|. The line B-B is furtherincluded in a plane that intersects the axis A-A of the bore at rightangles to said axis. When viewed from above, as in Figure 4, a planepassed axially through the Ibore 2| and including the axis B-B dividesthe bore'into substantially two equal diametrically opposedheini-cylindrical portions. Since the flat radial surface 22 is at rightangles to the axis A-A', diametrically opposed portions thereof, as at24--25, will be identically related to the axis B-B of the cross hole23-23.

The gauging instrument shown in Figures l, 5, 6 and '7 includes meansproviding a pair of non-parallel edges. This means in this form of theinvention preferably comprises a hardened steel gauge member 30 havingnon-parallel edges 3|and 32, these edges representing .respectively thebase and the hypotenuse of an imaginary right triangle. Forv purposesto-be set forth below,'the longitudinal'gauge member 3B is provided witha groove 33 running lengthwise thereof. Inasmuch as the gauge 30 isintended primarily for use in connection with curved surfaces, the edge3| is rounded on a slight radius. as indicated at 34 in Figure 2.

The gauge 30 carries for longitudinal adjustment thereon an indicatingmember 35 lwhich includes a head 36 and a projecting leg portion 31. Thehead '36 is slotted at 38 (Figure 2') to receive the gauge member 3|). Ascrew 39 passes through the head on an axis normal to the edge 3| of thegauge 30 and has a hooked end 'd that is slidably received in thelongitudinal groove 33. An adjusting Vnut 4| is threaded on the outsideend of the screw 39 and serves to hold the indicating member 35 in anyselected position on the gauge member 30. The construction may followclosely that of conventional adjustable squares.

The gauge-member 33 is provided along the base edge 3| thereof with ascale or indicia 45 in theform of a/'plurality of gradulations ordivisions'representing units of linear measurement. In the present case,thegraduations or divisions of the scale`45 are readable in thousandthsof an inch; although, it will be understood that any other'units oflinear measurement may be substituted therefor. In order that the scalemay be lreadily adapted to the most common inspection procedures, thescale 45 has been constructed so that the distance between eachgraduation is equal to 4one-thirty-second part of yan inch. Since, aswill hereinafter appear, it is only the differencesin readings, and Vnottotal distances 'with which the gauge is concerned, the graduations have-been numbered -at every fourth one thereof from 4to 10,0 and the.numbering is repeated thereafter. Inasmuch as A,the graduations uare,one-thirty-.second of ,an inch apart, therewill be thirty-twograduations per inch. In the drawings, certain of the graduations havebeen omitted to eliminate undue repetition, butl it will be understoodthat the graduations extend throughout the length of that portion of thegauge along the base edge 3|.

The taper of the edge 32 is uniform with re spect to the base edge 3|and is so constructed that the taper in the aforesaid unit ofmeasurement (thousandths of an inch) per inch is twice the number ofgraduations per inch on the scale 45. In other words, the scale 45 andthe taper ofthe edge 32 are arranged according to the formula whereinT=taper in thousandths of an inch per inch, and N=the number ofgraduations per inch on the scale 45.

I will now be set forth in connection with the necessary gaugingoperations for the checking of the part or article 20, as shown inFigure 5. As an adjunct to the use of the gauge member 30 there Aisprovided a checking pin or member 50 which is inserted in the cross hole23-23. The pin thus divides the bore 2| into two substantiallydiametrically opposed hemi-cylindrical portions. It is immaterialwhether the pin 50 fits the cross hole 23-23 loosely or tightly, since,as aforesaid, the concern of the gauge is with comparative readings andnot total distances.

In Figure 5, the axis of the cross hole 23-23 has been shown ol centerto the left of the axis A-A, as represented by the line C-C. The pin 5|)has a loose t in the cross hole 23-23. The gauge 30 is inserted as shownwith the straight edge 3| lying along an element of the innercylindrical surface of the bore 2| at the left side of the pin 50, thisedge thus engaging a surface portion of the bore 2| `diametrically atone side ',of thev pin. The gauge member is inserted so that a wedgingaction results because of engagement of the edge 3| with the surfaceportion and engagement of the tapered edge 32 with the left side of thepin 50, the pin being displaced to the right as illustrated. The extentof insertion of the gauge member 30 as aforesaid can be read on thescale 45 by noting the nearest graduation to the radial face portion 24at the left side of the part 20. In this case, it reads .017 inch. Thegauge member 30 is now withdrawn, reversed, an reinserted at theopposite side of the pin 5|), as shown in dotted lines in Figure 5. Thepin 50 Ywill now be displaced to the left, as indicated;

and, since the cross hole 23-23 is actually off center to the left, thegauge member 30 may be inserted to a greater extent than before. Thereading can then be taken on the scale 45 at the radial face portion 25.Since, as aforesaid, the radial face portions 24 and 25 bear the samerelationship to the true center of the cross hole 23-23, the comparativereadings will be arcuate. It will be noted in Figure 5 that the scale,in its dotted line position, has been inserted into the bore to anextent which will give, at 25, a reading on the scale 45 of .034 inch(not shown). 'I'he previous reading of .017 is subtracted from thereading .034 inch to give a result of .017 inch,

which is the amount that the axis of the cross lho1e123-23 is oif centeras respects the axis A--A of the bore A2 By way of explanation of therelationship of thetapered edge 32 to the base edge 3|, it should benoted, as an important feature of the gauge, that no mathematicalcomputations are necessary; the inspector merely makes the comparativereadings as stated above. The elimination of mathematical computationsis accomplished by arranging the taper so that it is equal inthousandths of an inch per inch to twice the number of graduations perinch on the scale 45; that is, the taper is .064 inch per inch and thereare thirty-twograduations per inch on the scale 45. If the taper were.032 inch per inch as compared to thirty-two graduations per inch on thescale 45, it would be necessary to take the readings at 24 and 25,subtract thesmaller from the larger, and divide the result by two,inasmuch as the gauge measures, in effect, the distance between theactual center of the cross hole and the proximate surface of the boreV2| at each side of the axis of the cross hole. However, the differencebetween the two distances is not the amount that the cross hole is offcenter as respects the axis A-A, since this difference must be dividedby two. For example, take the instance of a circle having a radius oftwo inches; select a point on a diameter of that circle one inch fromthe center of the circle. It will be found that the selected point isone inch from the proximate peripheral portion of the circle and threeinches from the remote peripheral portion of the circle on the samediameter. Yet, the eccentricity of the point is only one inch. Accordingto the pres ent invention, the computation covering this phase ofmeasurement is built into the gauge. It will be understood, of course,that the same result would follow in the event that diierent units oflinear measurement were used. In the case of checking extremely smallparts, wherein the bore and the cross hole would be small, a gauge couldbe constructed according to the above formula so that the scale 45 wouldhave sixteen graduations per inch, each representing a thousandth of aninch, and the taper of the edge 32 with respect to the edge 3| would be.032 inch per inch. In this respect, among others, the present casediffers materially from the ordinary taper gauge heretofore known andused for the purposes of measuring distances between two points. Noprior instrument known to applicant has been used for the purposeaforesaid; nor'has it included therein the feature of eliminatingmathematical computation.

The gauge as used in the checking procedure just described can be usedWithout the indicating member 35, inasmuch as the part 20 is providedwith the uniform diametrically opposed portions 24 and 25. However, manycases occur in which the surface surrounding the bore is irregular. Suchan instance is illustrated in Figures 6 and 7, wherein a part or articleis designated generally by the numeral 50 and is shown as having anaxial bore 6| and a cross hole 62. The part is further represented ashaving an irregular surface 63 at the mouth of the bore 6|, this surfacehaving a high point 64. In gauging a part such as this, the cross pin ormember 50 is used as in the instance described before, this pin beinginserted in the cross hole 62. The gauge 30, carrying the indicatingmember 35, is used as before; that is, the gauge member 30 is insertedbetween one side of the pin 50 and the `pin 50.

7 proximate surface of the bore 6|. The Aindicating member 35 is broughtdown on the member 30 until the leg or arm 31 contacts the high point 64on the part or article 60. Opposite edges of the head f36 :areaccurately machined rto provide portions cooperating with the scale 45,as at (i5 inFigure'S.

The reading on the scale 45 rat 65 is `i'l, which in Athousandths of aninch is .0.47. The scale is withdrawn from the position of Figure 6 andYis inserted at the opposite side of the pin as in Figure '7. vIn thisinstance, the cross hole 62 is accurate with respect to the axis of thebore 6| .andthe head 36 of the Aindicating member engages the high.point 64 in such manner that the reading lon the scale 45 (not shown inthis figure) will be the same as the previous reading.

vIn the. event that the cross hole were off center,

Aa difference in .the reading would be indicated by `a comparison of thereadings yand the extent of inaccuracy of the cross hole 62 couldreadily be determined. The underlying principles of the lconstructionand operation as set forth in connection with Figure are inherent in theuse of the complete scale as shown in Figures 6 and 7. The indicatingarm 31 makes it easy to take a reading on any point xed with respect tothe cross hole 62. In a similar manner, the reading'icould be taken inrelation to the cross pin 50 itself .by providing an indicating arm theequivalent of the arm 31 which would extend into the bore for adjustableengagement with the However, as a practical matter, the sizes of boreslikely to be encountered places too great a limitation upon analternative means of the-'type described. On the other hand, it is notoutside the scope of thev invention to employ the suggested means.

Those principles of the invention embodying the means providing a pairof non-parallel edges in which the taper of one is related to the scaleof another in the manner aforesaid is carried over into the modificationshown in Figures 8-11.

yIn connection with these figures, a part or article is shown at 10 asrepresentative of a shaft or similar part having an external cylindricalsurface intersected by a cross hole 1I. The gauge in thiscase preferablycomprises a carrier member which has rigidly fixed to one end thereofOpposite lengthwise la `first leg member 16. edges of the carrier member15 are `accurately machined and provide for carryingmeans in the form ofa head 11 to which is axed a second leg member 18. Both leg members 16and 18 project `alongside each other from the carrier i,

and 18 is such as to provide a rst or straight l edge 8| and anon-parallel or tapered edge V82, the former being on the leg member 16and the latter being on the leg member 1S. rEhe leg 16 is provided alongthe straight edge 8| with a `scale including indicia in the form ofgraduations similar to those on the member 3g; that is, the :graduationsalong the edge 8| are thirty-two per inch and represent thousandths ofan inch in the final analysis. The taper of the edge 82 with respect vtothe edge 8| is the same as the 8. taper .of the edge 32 with respect .tothe `edge 3l, previously described.

The use of this form of gauge means lis indicated in .Figure 8. The head11 is adjusted on the kcarrier to any `selected .position suilcient toinclude the thickness of the lindicated part of the shaft 19ltietweenfthe Vspaced apart .nonparallel edges 8| and 82. This distanceis not critical, except as aforesaid, since, as stated above, the gaugemeans is concerned with comparative .readings 'and not total distances.The leg16 is inserted into the cross hole 1| with the tapered edge 82riding on or engaging a portion of the external cylindrical surface ofthe part 1B. The fact that the Aleg 16 is narrower than the diameter ofthe cross hole 1| is immaterial, for the reasons stated above. Thewedging action that Voccurs because roi the engagement of the legs withthe portions indicated determines that the relationship of thecomponents is sufficient to provide for a reading on the scale on theleg 15, which reading is'taken at the portion of the part 15J in whichthe outer cylindrical surface intersects the scale, which in the presentinstance is a reading of 086 inch. The 4gauge means is now withdrawn andreinser'ted so that the leg 18 is at a diametrically opposite portion ofthe cylindrical surface of the part 10. A second reading is taken andthe tworeadings are compared, the diierence, if any, representing theamount Vin thousandths of Van inch that the axis of the cross hole 1| isoi` from the axis of the cylindrical surface of the part 10..

The description in this respect is abbreviated in the `interest ofavoiding repetition, since the underlying principles are the same asVthose discussed above in connection with the gauge member 3|). it willbe seen that all attributes of the gauge member 30 are present in thegauge member or instrument 15-82.

In the form of the gauge shown in Figure 12, the scale has been placedon an additional member to provide for reduction in over-all size of thegauge. Here, the gauge is similar to that shown in Figures 8-l1, and isused for checking the part 10 or a similar part. This gauge includes acarrier 85 a first leg 86 fixed Vto the carrier, a second leg 81 fixedto a head 88 which is adjustable on the carrier, and measuring meanscomprising a rod 8S vertically slidably carried at 'Sil on the carrierand having a 'TQ9I at its lower end. A pointer 92 is Vprovided at v9Dfor cooperation with a scale 93 on the rod.

The tapered relationship between the Vproximate edges of the legs 88 and31 is the same as Y that between the edges 3e and 3| of the Agauge ofFigures 1J! or .the edges 8| and 82 of the gauge of Figures 8-1'1. The.scale 93 is constructed like the scale 47s' and accomplishes the sameresult.

In use, the leg 86 is inserted into the crosshole 1| and the tapered`edge on the leg 81 `utilized to determine the relationship between oneside of the cross hole. and a point on .the outer surface of the part10. The rod 89 is moved downwardly inthe means 90 until the T 9|restsvon the upper portionof the part 18 across the crosshole 1|. 'Ihereading is taken 'on the scale 93-at 92. The gauge iswithdrawn,.reversed and the `operation repeated at the other side of thepart, just as in the case of the gauge of Figures 8-.11, except thatreadings are taken and compared :on theV scale 93 on the rod 89 ratherthan directly on theleg, as at 16.

Asstated above the units of measurement .employedmay be varied to suit,the particular measurement systems employed. Similarly, the componentsof the gauges may be made of dierent sizes to accommodate larger orsmaller parts, it being readily conceivable that the gauges could beprovided in sets for that purpose, thus eliminating an extremely longuniversal gauge. These gauges could also be used on parts of polygonalor other sectional shapes. However, either expedient may be resorted toif desired. Other alterations and modications in the preferred forms ofthe invention illustrated may be resorted to Without departing from thespirit and scope of the invention as defined in the appended claim.

What is claimed is:

For use in gauging an article having a bore and a cross hole crosswiseof the bore; gauge means for checking the relationship of the cross holeto the bore, comprising a gauge pin of a diameter no greater than thatof the cross hole and adapted to be instered through the cross hole andof suiilcient length to extend across the bore so as to be spacedradially from a proximate inner surface of the bore; an elongated gaugemember having divergent longitudinal edges and provided along one ofsaid edges with measuring means including indicia representing divisionsof a unit of measurement, said divergent edges tapering from a large endof the member wider than the distance between the one side of the gaugepin and the proximate inner surface of the bore to a small end narrowerthan said distance so that the member may enter and be lightly wedgedacross said radial space; and an arm carried on the member foradjustment lengthwise of the member and engageable with an externalportion of the article and cooperative with said indicia to provide forreading of said indicia as to the extent of entry of the member intosaid radial Space.

RAYMOND D. HUBBS.

REFERENCES CTED The following references are of record in the file oi'this patent:

UNITED STATES PATENTS

